Transport in carbon nanotubes: Contact models and size effects

We present electronic transport calculations for single wall carbon nanotubes (CNTs) using two highly idealized models to describe the electrodes and their contact to the CNT. In the first model we use CNT-electrodes and in the second one we apply the wide-band approximation, neglecting any atomic structure within the electrodes. The single orbital tight-binding approximation is used to describe the electronic structure of the CNTs. This enables us to apply highly efficient decimation techniques to reduce the size of the finite central Hamiltonian. Semi-infinite CNT-electrodes can be included iteratively using a similar method. Electronic transport calculations are carried out within the Landauer formalism. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim